In order to extend capabilities in the study of the effect of amino acid sequence on protein function, a novel enzymatic resynthesis method was applied to several noncovalent fragment complexes. A success in coupling non-associating peptide fragments promised the enzymatic condensation as a viable method. In order to examine the roles of local versus long range interaction in determining the conformation of S-peptide in RNase-S, X-ray crystallography method is utilized. Crystals of S-peptide fragment (11-15) suitable for high resolution work were obtained and the structure is being investigated. Further refinement of (4-F-His12, 1-15)SRNase S is being carried out also.